Variable-stroke fluid pump



Dec. 22,1925.

VARIABLE STROKE FLUID PUMP Fild 0012. 20 1920 3 a. @Hf. /l// Patented Dec. 22, 1925.

UNITED STATES` l 1,566,813 PATENT OFFICE.

EMANUEL BLAUHOBN AND OTTO HAJ'EK, OF VIENNA, AUSTRIA..

VARIABLE-STROKE FLUID PUMP.

Application tiled October 20, 1920. Serial No. 418,291.

(GRANTED UNDER THE PROVISIONS 0F THE ACT 0F MARCH 3, 1921, 41 STAT. L., 1313.)

To all whom t may concern:

Be it known that we, EMANUEL BLAUHORN and O'rro HAJEK, citizens of the Republic of Austria, residing at Vienna, in the Republic of Austria, have invented certain new and useful Improvements in Variable-Stroke Fluid Pumps, of which the following is a specification.

This invention relates to a valveless pump for liquids, by means of which two places may be served under either the same or different pressures by a single pump piston.

The pump comprises a piston which is moved by means of a cam-shaped disc through the intermediary of an oscillating lever having a variable stroke, in such a manner that the piston performs two strokes n at each revolution of a driving shaft, while the distributing piston performs only one stroke at each revolution of the shaft with which it is connected by means of an eccentric.

According to this invention the piston performs a complete reciprocation at each half revolution of the drivlng shaft and this by a positive driving mechanism acting in both directions. This mechanism consists of a double cam, cooperating with an actuating lever having two lingers or lugs, one of which preferably is provided with an antifriction roller. The other linger or lug of said lever carries an internally threaded sleeve through which extends a screw spindle. The antifriction roller carried by one iin er or lug of said lever and the lend of sai screw spindle carried by the other finger or lugbear alternately upon said cam. The shape of the cam and the position of the finger or lug which carries the free end of the screw spindle and that which carries the antifriction'roller are so chosen, that the cam impinges only upon the end of the spindle or the roller at one time; but when the cam ceases to contact with thefree end of the spindle or with the roller, it comes immediately into contact with' the other and begins to move it, whereby the lever controlling the piston movement is continually positively moved to and fro by the double cam. The two faces of the double cam now cause a movement in both directions during one half revolution of the cam.

This arran ement makes it possible to use the same sha for controlling both pistons, one 0f them being moved by the said double cam with a double speed, so that it performs a complete reciprocation while the other is moved by an ordinary cam embraced by a fork or double lever contacting with two opposite faces of the samen once in one direction at each half revolution of the shaft.

In the accompanying drawing Fig. 1 shows an elevation of the pump partly in section, the distributing and-pump pistons being in different vertical planes.

Fig. 2 shows la top view of the driving shaft with the cams and actuatin levers.

1 is the pump piston, working 1n the cylinder 1 and 2 is the distributing piston. According to the position of the distributing piston 2, the li uid is forced either through channel 3 or t rough channel 4. 5 is the intake of the oil. If, for example, the steam inlet to a cylinder were closed, lubricatin oil might be supplied through the channe 3 to the cylinder at low pressure and at another time through the channel 4 tothe steam chest at the pressure of the boiler, according to the positions of the pump piston 1 and the distributing piston 2.

The pistons are reclprocated by the following driving mechanisms.

On the driving shaft 6 a double cam 7 which is provided with two eccentric faces is lixedly mounted. A rocking lever 8 is connected with the pump piston 1 by means of a finger which extends into a slot of the said piston or is otherwise connected therewith in such a manner, that relative movement of the connected parts is possib e.

The said rocking lever 8 is provide with a pair of additional fingers or lugs 12`Gand 13 which project into proximity to the periphery of the cam 7, both of said fingersv oi. lugs 12 and 13 being bifurcated. An antifriction roller 14 is rotatably mounted in the bifurcation of the finger or lug 12, and an internally screw-threaded sleeve 15 is mounted to rock on pivots in the bifurcation of the linger or lug 13. The spindle 9 is vscrew- 100 threaded adjacent its lower end to engage the internal screw-threads of the sleeve 15 and has itslower end projecting below the lower end of said sleeve into the path of the cam 7.

The faces of the double cam 7. are so shaped 105 that only the end of the spindle carried by I one fin er or lug or the roller carried by the other nger or lug will contact with the periphery of the cam at one time. When the cam, while rotating with the shaft and press- 110 ingupon the end of the spindle 9 carried by one finger or lug, moves out of contact with the end of said spindle, it immediately engages the roller carried by the other finger or lug and begins to press upon the same Whereby the lever is rocked in opposite direction. As the cam is provided with two faces and the lugs or fingers are arranged approximately at a right angle to one another, each half rotation of the shaft will cause a complete reciprocation of the pump piston 1,-

since once during each half revolution of the shaft-one of the two faces of the cam impingespiirst upon the free end of the spindle 9 and then upon the roller carried by the respctive lugs or iin ers thus moving the roc 'ng lever 8 in bot directions. During the other half revolution of the shaft the second face of ythe double cam imparts the same movement to the lever and the piston 1. lt will be seen from the above that the whole movement of the piston is positively controlled by the double cam cooperating with the end of the spindle 9 and the antifriction roller carried by the respective fingers or lugs.

The distributing piston 2 is driven by an eccentric 10 mounted on the driving shaft 6 at an angle of 90 to the cam 7, the drive being through a rocking lever l1 provided with a fork at one end, which encloses the eccentric in the well known manner, while the other end is provided with a finger extendine' into a slot of the distributing piston 2 or being otherwise connected with sald pisv ton in such manner that relative movement of the parts is permitted.

Thus it will be seen that-the piston 1 performs two strokes for every 'stroke of the piston 2, the latter having an advance of one half strokeowing to the fact that both eccentrics are keyed on the shaft at an angle of 90. Both pistons are positively driven during their whole' stroke and the above arrangement makes it possible, notwithstanding such positive driving, to have both driving eccentrics mounted on the same driving shaft.

What we claim is l. In a valveless Huid pump having a pump piston and a distributing piston,

means to reciprocate both pistons positively comprising a drivin shaft, a cam on said driving shaft, a roc ing lever in operative connection with the distributing piston, a fork on said lever enclosing the cam to edect positive control of the movement of said ever, a second cam on said driving shaft provided with a pair of faces, a rocking lever adjacent to said second cam in operative connection with the pump piston, and two lugs on said lever adapted to come alternately in operative contact with each of the faces of said pair to effect positive driving of the piston in both directions at a speed double to that of the distributing piston.

Y 2. In a valveless iuid pump having a pump piston and a distributing piston, means to reciprocate both pistons by positive drive, comprising a single drivingshaft, two cams fixed on said shaft, a rocking lever in operative connection with one of said cams and the distributing piston, a second rocking lever in operative connection with the pump piston, the latter lever being provided with two lugs extending in proximity to the periphery of the second cam, a pair of faces on said second cam extending in different directions and impinging upon said lugs, the lugs of the second-named lever being arranged in such a manner that they are alternately contacting with each of the faces of said second-named cam and are moved thereby in did'erent directions at the passage of each of the faces as to eect positive movement of the piston by means of the rocking lever in both directions at a speed double to that of the piston moved by the other cam.

3. In a valveless Huid pump having apump piston and a distributing piston, means to reciprocate both pistons by positive drive, consisting of a driving shaft, acam keyed on said shaft, a rocking lever in operative connection with the cam and the pump piston, a second cam provided with two faces keyed on the shaft at an `angle of 90 to the first cam,a rocking lever provided with two lugs arranged at approximately a right angle to one another and adapted to come alternately in contact with each of said faces, each of the faces effecting a positive to and fro movement of the rocking lever and of the iston connected therewith, the pump iston eing reciprocated twice by means lof t e two faces durlng one reciprocation of the distributing piston.

In testimony whereof we have `hereunto set our hands.

'EMANUEL BLAUHORN. OTTO JEK. 

